What it means

Your request body did not pass PreVOP's input validation, so the gateway refused it before contacting the upstream VOP provider. The response includes a title and detail naming the first field that failed and why.

When you'll see it

• A required field is missing from the JSON payload.
• A string exceeds its maximum length (for example party.name is capped at 140 characters per EPC 267-24).
• A field contains characters outside the EPC-permitted set.
• An IBAN fails the ISO 7064 mod-97 checksum.
• A BIC is the wrong length for the configured provider (8 or 11 characters).
• The request body exceeds the configured size limit (default 10 KB).

Example response

HTTP/1.1 400 Bad Request
Content-Type: application/problem+json
X-Request-ID: 550e8400-e29b-41d4-a716-446655440000

{
  "type":    "https://errors.prod.prevop.alseda.eu/errors/validation-failed",
  "code":    "VALIDATION_FAILED",
  "title":   "party.name: name too long (max 140 chars)",
  "status":  400,
  "detail":  "party.name: name too long (max 140 chars)"
}

How to fix

1. Read the title — the first failing field is named there, followed by the rule that was violated.
2. Read detail for the complete explanation, and issues[] (when present) for the full list of problems in the payload.
3. Compare your request against the OpenAPI specification to confirm the expected shape, types, and constraints.
4. Correct the field, then resend the request with a fresh X-Request-ID (a retry with the same ID may be rejected as a duplicate by quota controls).

Related

• Customer API Contract §4.1 — Error envelope format
• Customer API Contract §4.2 — PreVOP error codes (VALIDATION_FAILED row)
• See also: FORMAT_ERROR — same underlying shape check, when the failure is detected upstream instead of at the gateway.